Have you ever wondered about the physical science of popping corn? What makes a corn kernel pop into a light and fluffy flake? Scientists have studied popcorn in the lab and their findings have been used by the food industry to develop new varieties. Some of the improved stocks insure a greater percentage of kernels that pop. Others have kernels that pop into larger, fluffier flakes. Critics, however, argue that these commercial advantages compromise the true corn taste.
Pop goes the kernel
Do you enjoy eating popcorn? If so, do you have a brand you prefer? What makes that brand different from other types of popcorn? In this activity, you’ll compare several brands of this snack food and see how all popcorn is not created equal.
Materials: Three varieties of popped popcorn samples Three plates Ruler Graph paper
Steps: 1. Place five representative flakes of one brand of popped corn on a plate.
2. Select one flake of the popped corn. Use a ruler to measure the length of the flake long its longest axis. Record the value in the table below.
3. Then, determine its greatest width. The width is measured at a right angle to the length axis. Record the value in the table below.
4. Finally, determine the height of the flake. The height is the measurement taken at a right angle to the plane of the length and width (at the point of their intersection). Record this value in the table below.
5. Determine the average length, height, and width of the other flakes.
6. How would you describe the general shape of a typical flake? Is it round? Is it irregular?
7. Select a representative flake. Place it on a sheet of graph paper. Sketch the general shape of the flake on the grid. Make additional sketches that illustrate the shape of two other kernels.
8. Repeat steps one through seven using two other brands of popcorn.
9. Compare and contrast measurements of the different brands.
1. Which brand had the longest average flake length? Which brand has shortest average flake length?
2. Add up the average length, wide, and height measurement for each brand. Which brand has the greatest sum of these dimensions? Which one has the smallest sum of dimensions?
3. Compare the sketches of the popcorn flakes. Which brand had the roundest flakes? Which had the most irregular?
Turn to the table of contents in this issue. Examine the strobe photo of a kernel exploding into a popped flake. On a scrap pad of paper, create a flipbook animation that illustrates the formation of a popcorn flake. Share your animation with other students.
Selling an idea
Some popcorn aficionados believe that many major commercial brands of popcorn have lost the true flavor of this treat. Although they may pop better, they don’t taste as good as other varieties. Suppose you were in charge of marketing these brands to the public. What strategies would you use in your marketing campaign to address the pop versus taste dilemma?
Releasing the pressure
Suppose the shell of an unpopped kernel was cracked? How might a crack affect the explosion of the kernel into a fluffy flake? Make a prediction. Then, create a strategy for inquiry to address this question. Share your experimental design with your instructor. With his or her approval, perform the experiment. Report your findings to your classmates.